Final answer:
Among the services listed, maintaining the national defense is a service provided by the federal government. This function includes the armed forces and is central to the federal government's role in protecting the entire nation. The correct option is B).
Step-by-step explanation:
The service provided by the federal government listed in the student's options is maintaining the national defense. Federal responsibilities include a variety of functions such as advancing national defense, helping workers as a group, helping industries stay strong, and protecting the environment. However, among the provided options:
- Collecting garbage and recyclable items is typically a municipal government responsibility.
- Operating both police and fire departments is usually managed at the local level, as these services are tailored to the needs of individual communities.
- Setting education standards for children is often a state function, although the federal government can influence these standards through policies and funding.
- Maintaining the national defense is unequivocally a federal government role, as this involves the armed forces that protect the entire nation.